The Quadriceps angle (Q angle) in Indian men and women

Raveendranath V., Nachiket S., Sujatha N., Priya R., Rema D.

ABSTRACT The quadriceps angle (Q angle) is a clinical measure of the alignment of the quadriceps femoris musculature relative to the underlying skeletal structures of the pelvis, femur and tibia. The aims of this study were to calculate the Q angle in a young, healthy adult Indian population in order to document any significant differences in the Q angle between males and females and to analyze these differences. Two hundred limbs (100 from males and 100 from females) from healthy adult Indian volunteers were studied. The Q angle was measured using a goniometric method with the subjects supine, the quadriceps relaxed and the lower limbs in neutral rotation. Lateral placement of the tibial tuberosity with respect to the centre of the patella was measured. Inter-observer variations in the above mentioned parameters were studied in twenty limbs. The average Q angle value of all 200 limbs was 12.73° ±2.58. The mean value in females was 14.48° ±2.02 and 10.98° ±1.75 in males. The lateral placement of the tibial tuberosity was 0.9 ±0.59 cm and 1.8 ±0.65 cm in males and females respectively. Both the Q angle and the lateral placement of the tibial tuberosity were significantly greater in females. The intra-class correlation coefficient was 0.66 for the Q angle and 0.8 for the lateral placement of the tibial tuberosity. Females had a significantly greater Q angle as compared to males as a result of a more laterally placed tibial tuberosity.